This invention relates to a vacuum insulating glass (IG) unit, and a method of making the same. More particularly, this invention relates to a vacuum IG unit including fiber spacers.
Vacuum IG units are known in the art. For example, see U.S. Pat. Nos. 5,664,395, 5,657,607, 5,891,536 and 5,902,652, the disclosures of which are all hereby incorporated herein by reference.
Prior art FIGS. 1-2 illustrate a conventional vacuum IG unit. IG unit 1 includes two spaced apart sheets of glass 2 and 3 which enclose an evacuated or low pressure space therebetween. Glass sheets 2 and 3 are interconnected by peripheral or edge seal of fused solder glass 4 and an array of support pillars or spacers 5.
Pump out tube 8 is sealed by solder glass 9 to an aperture or hole 10 which passes from an interior surface of glass sheet 2 to the bottom of recess 11. A vacuum is attached to tube 8 so that the cavity between sheets 2 and 3 can be evacuated to create a low pressure area. After evacuation, tube 8 is melted to seal the vacuum. Recess 11 retains melted and sealed tube 8. Chemical getter 12 may be included within machined recess 13.
Certain conventional pillars 5 disposed between the opposing substrates are either too soft (e.g. certain metals) or too hard (e.g. certain ceramics). These may cause either heat disturbances in the unit due to high thermal conductivity, and/or contact damage (e.g. cracks) in the glass substrate(s). Moreover, certain conventional sharp or compact pillar shapes may invoke significant point-loading on small areas of the glass substrate(s), especially in the case of pillar height variations, thereby leading to potential scratching and/or cracking of the substrate(s).
Still further, certain conventional metal pillars appear as colored, opaque, and/or light reflecting dots in the viewing area of the window. Some viewers may believe this to be aesthetically displeasing.
It is apparent from the above that there exists a need in the art for a vacuum IG unit, and corresponding method of making the same, including improved spacers between opposing glass sheets or substrates. There also exists a need in the art for fiber inclusive spacers for use in vacuum IG window units.
This invention will now be described with respect to certain embodiments thereof, accompanied by certain illustrations.
An object of this invention is to provide a vacuum insulating glass (IG) unit including a plurality of fiber or strand spacers horizontally aligned between the opposing glass substrates.
Another object of this invention is to provide a vacuum IG window unit including a plurality of substantially transparent fiber spacers between the opposing substrates. xe2x80x9cSubstantially transparentxe2x80x9d means the spacers are at least about 70% transparent to at least some visible wavelengths of light.
Another object of this invention is to provide a vacuum IG window unit including a plurality of fiber spacers that are at least about 80%, most preferably at least about 90%, transparent to at least some (and most preferably all) wavelengths of visible light.
Another object of this invention is to provide a vacuum IG window unit including a plurality of elongated glass fiber spacers.
Another object of this invention is to provide a vacuum IG window unit including a plurality of elongated fiber spacers distributed in either a random or uniform manner across a viewing area of the unit in order to space the opposing glass substrates from another.
Another object of this invention is to provide a vacuum IG window unit including a plurality of fiber spacers having an index of refraction approximately the same as (i.e. within about 10% of) the index of refraction of at least one of the glass substrates.
Another object of this invention is to fulfill any and/or all of the above-listed objects.
Generally speaking, this invention fulfills any or all of the above described needs and/or objects by providing a thermally insulating glass panel comprising:
first and second spaced apart glass substrates defining a low pressure space therebetween having a pressure less than atmospheric pressure;
a plurality of elongated fiber spacers disposed between said first and second glass substrates across at least a portion of a viewing area of said panel for spacing said substrates from one another in order to maintain said low pressure space therebetween; and
at least one seal disposed between said first and second glass substrates for hermetically sealing said low pressure space.
This invention further fulfills any or all of the above described needs and/or objects by providing a method of making a vacuum insulating glass (IG) window unit comprising the steps of:
providing first and second glass substrates;
providing a plurality of fiber spacers between the first and second substrates for spacing the substrates from one another so as to define a low pressure space therebetween having a pressure less than atmospheric pressure; and
forming a seal for sealing the low pressure space between the substrates.